1. Field of the Invention
This invention relates generally to a system and method for monitoring the state of health and providing fault diagnosis for components in an integrated vehicle stability system, by-wire vehicle, vehicle active control system, etc. and, more particularly, to an adaptive fuzzy logic based state of health and fault diagnosis monitoring system for a vehicle employing an integrated stability control system, by-wire vehicle, vehicle active control system, etc.
2. Discussion of the Related Art
Diagnostics monitoring for vehicle stability systems is an important vehicle design consideration so as to be able to quickly detect system faults, and isolate the faults for maintenance, control reconfiguration, tolerance and fail safe purposes. These stability systems typically employ various sensors, including yaw rate sensors, lateral acceleration sensors, wheel speed sensors and steering hand-wheel angle sensors, that are used to help provide the stability control of the vehicle. For example, certain vehicle stability systems employ automatic braking in response to an undesired turning or yaw of the vehicle. Other vehicle stability systems employ active front-wheel or rear-wheel steering that assist the vehicle operator in steering the vehicle in response to the detected rotation of the steering wheel. Other vehicle stability systems employ active suspension stability systems that change the vehicle suspension in response to road conditions and other vehicle operating conditions.
If any of the sensors, actuators and sub-systems associated with these stability systems fail, it is desirable to quickly detect the fault and activate fail-safe strategies so as to prevent the system from improperly responding to a perceived, but false condition. It is also desirable to isolate the defective sensor, actuator or sub-system for maintenance and replacement purposes, and also select the proper fail-safe action for the problem. Thus, it is necessary to monitor the various sensors, actuators and sub-systems employed in these stability systems to identify a failure.